Statorless Rotor Torque Control Without High-Frequency Inverters
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Solution Overview
Problem
Existing electric motors, particularly those used in Electric Vehicles, suffer from inefficiencies such as sparking, heat, vibration, cogging, corrosion, high frequency power inverter requirements, torque ripples, noise, and structural damage due to high frequency alternating magnetic fields, leading to complex monitoring and maintenance needs.
Innovation Solution
A statorless electromechanical device comprising rotors with toroidal rings, petal units, magnetic cores, and coils, utilizing a controller to manage petal unit activation and deactivation for unidirectional torque generation, eliminating the need for stators and reducing reliance on high-frequency inverters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If mechanical commutation is used in DC motors, then the motor can operate at lower speeds with simple structure, but it causes sparking, heat, vibration, cogging, corrosion and has limited RPM
Solution Approach 1:
The patent removes the stator component entirely from the motor design, extracting the source of mechanical commutation problems. By eliminating the stator, the invention avoids sparking, heat, vibration, and cogging associated with mechanical commutation while maintaining motor functionality through rotor-only construction with permanent magnets and conductive segments.
Solution Approach 2:
The patent inverts the traditional motor architecture by placing permanent magnets on the rotor instead of the stator. This inversion transforms the motor from a mechanically commutated system to a statorless design where the rotor generates the magnetic field, fundamentally changing how torque is produced and eliminating the need for mechanical commutation components.
2Speed
If synchronous and Induction motors use high frequency 3-phase AC with power inverters and VFD, then high RPM rotating magnetic field is generated, but it causes power factor losses requiring bulky capacitor banks
Solution Approach 1:
The patent removes the stator and its associated power inverter and VFD systems, extracting the source of power factor losses. By eliminating these components and using direct DC excitation of rotor coils, the invention achieves high RPM without the energy losses and bulky capacitor banks required by traditional AC motor systems.
Solution Approach 2:
The patent replaces the complex electrical control system (power inverter, VFD, capacitor banks) with a simpler direct DC excitation system. This substitution eliminates power factor losses by using DC-powered coils on the rotor that generate the rotating magnetic field directly, without requiring high-frequency AC conversion and power factor correction.
3Extent of automation
If SRM and BLDC motors use high frequency inverter power electronics with Hall effect sensors, then electronic switching is achieved, but it produces lower torque and suffers from cogging, vibrations, noise, and switching losses
Solution Approach 1:
The patent removes Hall effect sensors and high-frequency inverter power electronics from the motor system, extracting the sources of switching losses and control complexity. By using a statorless design with direct DC excitation and controller-based petal unit activation, the invention achieves electronic control without the torque reduction and losses associated with traditional electronic switching systems.
4Speed
If DC motors use PWM to control speed and torque, then variable speed operation is achieved, but it requires specialised inverter power electronics causing efficiency reduction, torque ripples, vibration, and noise
Solution Approach 1:
The patent removes the need for PWM switching and specialized inverter power electronics by using direct DC excitation of rotor coils. The controller activates and deactivates petal units (coils with magnetic cores) directly using DC power, achieving variable speed and torque control without the switching losses, torque ripples, vibration, and noise inherent in PWM-based systems.
5Power
If high frequency alternating magnetic field is used to generate torque, then motor operation is achieved, but it causes hysteresis in ferromagnetic cores and eddy currents in metallic materials resulting in heating and structural damage
Solution Approach 1:
The patent removes the stator and its high-frequency alternating magnetic field generation system, extracting the source of hysteresis and eddy current losses. By using DC-powered coils on the rotor that create a rotating magnetic field through physical rotation rather than high-frequency alternation, the invention generates torque without the heating and structural damage caused by hysteresis and eddy currents in ferromagnetic cores and metallic materials.
6Strength
If permanent magnets are used in the rotor, then magnetic field generation is achieved, but they suffer hysteresis loss, magnetostriction, and degradation of strength over time
Solution Approach 1:
The patent employs a hybrid rotor design where permanent magnets are combined with electromagnets (coils that can be activated and deactivated). This dynamic configuration allows the system to use permanent magnets for baseline magnetic field generation while supplementing or replacing them with electromagnets when additional torque is needed, reducing the burden on permanent magnets and mitigating their hysteresis loss, magnetostriction, and strength degradation over time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device achieves efficient torque control with reduced vibrations, noise, and structural damage, enhancing durability and efficiency by optimizing torque generation and minimizing the need for complex power electronics.
Implementation Method 1
The one or more coils are configured to carry a first force orthogonal to the magnetic field while conducting electric current for generating the unidirectional torque through a second force. The first force is electromagnetic force, and the second force is Lorentz force.
Implementation Method 2
The one or more coils are configured to carry a first force orthogonal to the magnetic field while conducting electric current for generating the unidirectional torque through a second force. The first force is electromagnetic force
Implementation Method 3
The one or more magnetic cores are configured to provide a flux path for guiding magnetic field to produce the unidirectional torque
Implementation Method 4
Each rotor is configured with a defined configuration of variable reluctance mechanism for inductive power transfer to receive electric current from a power source
Data Source
AI summary
A statorless electromechanical device and a method thereof, are disclosed. The statorless electromechanical device comprises rotors. Each rotor is configured with a defined configuration of variable reluctance mechanism for inductive power transfer to receive electric current from a power source. Each rotor comprises toroidal rings, petal units, and a controller. The petal units comprise magnetic cores, non-magnetic sheets, pairs of magnets, and coils. The magnetic cores provide a flux path for guiding magnetic field to produce a unidirectional torque. The pairs of magnets generate the magnetic field. The coils carry a first force orthogonal to the magnetic field while conducting electric current for generating the unidirectional torque through a second force. The controller trigger activation and deactivation of defined petal units for controlling the generated unidirectional torque.